High temperature cyclic oxidation behavior of Y₂O₃-ZrO₂ thermal barrier coatings irradiated by high-intensity pulsed ion beam

Abstract

The high-temperature oxidation resistance behavior of 7% (mass fraction) Y₂O₃-ZrO₂ thermal barrier coatings (TBCs) irradiated by high-intensity pulsed ion beam (HIPIB) was investigated under the cyclic oxidation condition of 1 050 °C and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100–200 A/cm² and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide (TGO) layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm² due to the oxidation are found to be 0.8–0.9, 0.6–0.7, and 0.3–0.4 mg/cm², respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs.

Keywords

Y₂O₃ / ZrO₂ / thermal barrier coating / high-intensity pulsed ion beam / electron beam physical vapor deposition / oxidation resistance / cyclic oxidation